React & redux. Through redux i came in touch with functional programming. During the first week learning it, i came home from work exhausted and with a headache

React & redux. Through redux i came in touch with functional programming. During the first week learning it, i came home from work exhausted and with a headache but eventually it clicked and i was amazed how productive and bugfree further development was. I began to adapt the functional style in my PHP projects and started using real functional programming languages (Elixir and F#) to take my understanding even further. Still plenty to learn.